1. Field of the Invention
This invention relates to a novel vaccine against motile Aeromonas septicemia which does in fact provide superior protection over commercial treatment involving feeding medicated feeds.
2. Description of the Relevant Art
Aeromonas hydrophila, a free-living, Gram-negative bacterium, is one of the most common bacteria in freshwater habitats worldwide. A. hydrophila infection results in hemorrhagic septicemia and heavy mortalities in cultured and wild fish. Antibiotics and chemotherapeutic drugs have been used for disease management in feed additives and in direct administration into fish pond water; however, there has been an increase in drug resistant strains (Son et al. 1997. Letters in Appl. Microbiol. 24: 479-482; (Harikrishnan and Balasundaram. 2005. Reviews in Fisheries Science 13: 281-320). Extensive research efforts and strategies have not yet resulted in the development of a safe and effective vaccine. There is still no product that has been licensed for use against the motile aeromonads within the United States (Cipriano, R. C. 2001. Revision of Fish Disease Leaflet 68, U.S. Dept. Interior, Fish and Wildlife Service Div. of Fishery Res., Washington, D.C.). Thus, there is a need, particularly in the aquaculture industry, for an efficacious and safe vaccine.